<!DOCTYPE html>
<htm1>
<head>
    <meta charset="utf-8"/>
    <title></title>
    <style type="text/css">
        .lv{color:red;}
</style>
</head>
<body>
<div>绿叶学习网</div>
<div class="lv">绿叶学习网</div>
<div class="lv">绿叶学习网</div></body>
</htm1>